PFAS levels in English rivers fell by nearly a third over a decade, figures show

Concentrations of two long-lasting PFAS chemicals in English rivers have fallen by nearly a third over the past decade, according to new Environment Agency figures reported by the BBC. Levels in freshwater fish have also dropped, although the published figures do not specify which chemical the fish result refers to.

The BBC reported falls of 30% for PFOS and 29% for PFOA in rivers, and a 49% decline in freshwater fish. The Environment Agency figures were published on Thursday, the BBC said.

PFOS and PFOA are among the best-known per- and polyfluoroalkyl substances, or PFAS. These chemicals are slow to break down in the environment, earning them the name “forever chemicals”. PFOS was largely banned in the UK in 2010 and PFOA in 2020, following concerns about their effects on health and wildlife.

The BBC attributed the declines to tighter restrictions on the chemicals’ use. It quoted Dr David Megson, a reader in environmental forensics at Manchester Metropolitan University, as saying: “It’s brilliant to see how far we have come in the last 10 years.”

Lower concentrations do not necessarily mean less PFAS remains in the environment. The Environment Agency report, as described by the BBC, said the overall amount may have remained unchanged because the chemicals have been diluted and washed into the sea.

Thousands of other PFAS are thought to exist, though the BBC reported that only about 200 are frequently used. The Environment Agency said uncertainty remains about the toxicity of many of them and called for PFAS to be regulated as a group rather than one chemical at a time. The chemical industry has argued that evidence of toxicity for some alternatives is limited and that certain PFAS have important uses, including in life-saving medical equipment.

The agency is now regularly testing for 60 other PFAS to build a picture of contamination. A separate government wildlife indicator reports declining PFOS concentrations in freshwater, but its latest data run only to 2022 and do not establish the specific percentages reported in the new figures.